The High-Cost-Catch (Kogaku Ryoyohi) System

The High-Cost-Catch System Japan residents rely on caps covered medical spending per calendar month by income, so a large hospital bill does not scale without limit.¹ A typical-income worker who incurs 1,000,000 JPY of covered care in one month pays about 92,940 JPY under the current formula, with the insurer absorbing the rest.² This article maps the formula, the brackets, and the two payment routes.

Confirm current details with official sources

Procedures, fees, and requirements can change. Confirm current details at the Ministry of Health, Labour and Welfare (MHLW). This article is general information, not medical advice; for your specific case, consult a licensed medical provider and your insurer.

Overview

Japan public insurance normally asks patients to pay 30 percent at the counter while insurance pays 70 percent. The High-Cost-Catch adds a second cap on top of that share for covered care in a single month.¹

Once monthly covered copayments pass a personal ceiling, the excess comes back from the insurer or is never charged. The ceiling follows age and income, and the system covers every enrolled resident the same way.¹³

Who is already covered

The 高額療養費制度 (kogaku ryoyohi seido, "high-cost medical expense benefit system") is built into both public schemes, so there is no separate signup.³ Employees use health insurance through Kyokai Kenpo or a company society, while self-employed residents and others use National Health Insurance at the ward or municipal office.²

Anyone staying 3 months or more must enroll in one scheme and then holds the same protection regardless of nationality.¹ To find the right counter, read the insurance card: a company or society name points to that insurer, a municipality name points to the municipal National Health Insurance counter, and a wide-area union name points to that union.¹

How the monthly cap works

The cap applies per calendar month, from the 1st to the last day, to covered treatment only.¹ The 自己負担限度額 (jiko-futan gendogaku, "monthly out-of-pocket ceiling") is the most the household pays for that month; the insurer absorbs the covered excess above it.³

For the upper and middle under-70 brackets, the formula is a base amount plus 1 percent of total covered cost above a threshold (as of 2026-07-31; confirm current figures with MHLW or your insurer).³ Total covered cost means the full 100 percent insured figure, not the 30 percent paid at the counter (as of 2026-07-31).³

A worked example at typical income

Take a typical-income resident in bracket ウ (annual income about 3.7M to 7.7M JPY) with 1,000,000 JPY of covered care in one month. The current ceiling is 85,800 plus 1 percent of 714,000, which equals 92,940 JPY (as of 2026-07-31).²

The patient share without the system would be 300,000 JPY at 30 percent. The benefit therefore covers roughly 207,000 JPY of that month (as of 2026-07-31).²

MHLW illustrates the same point with a 1,000,000 JPY treatment capped near 93,000 JPY for the under-70 middle band under the revised scheme (as of 2026-07-31).¹ The exact band edge differs slightly by presentation, so confirm your band with your insurer before relying on the illustration.

What the formula leaves out

Only insured-treatment copayments count toward the ceiling. Extra-bed differentials, hospital meal and living costs during admission, and non-insured or advanced-care technology fees sit outside the benefit and are paid in full on top (as of 2026-07-01).³⁴

The MHLW English explainer lists the same exclusions, including private-room charges, pajama rental, food service, and non-covered advanced care.⁵ Review before admission can reduce these extra charges, since they carry no upper limit.

Budget private-room and meal charges outside the monthly ceiling

The monthly ceiling never covers the private-room differential or hospital meals. A capped treatment month can still produce a large bill when these extras stack on top.³⁴

Income brackets and ceilings

Ceilings step by income band and age, with five under-70 bands labeled ア to オ (as of 2026-07-01; confirm current figures with MHLW or your insurer).³⁴ The formula is set nationally, so the same table applies anywhere in Japan and only the application counter differs by insurer. The table below shows both the pre-reform month ceilings and the current ones, since treatment months before and after August 2026 use different bases.

Band	NHI income basis	Monthly ceiling to July 2026	Monthly ceiling from Aug 2026	As of	Multiple-occurrence
ア	over 9.01M JPY	252,600 + (cost minus 842,000) x 1%	270,300 + (cost minus 901,000) x 1%	2026-0742	140,100
イ	6.0M to 9.01M JPY	167,400 + (cost minus 558,000) x 1%	179,100 + (cost minus 597,000) x 1%	2026-0742	93,000
ウ	2.1M to 6.0M JPY	80,100 + (cost minus 267,000) x 1%	85,800 + (cost minus 286,000) x 1%	2026-0742	44,400
エ	up to 2.1M JPY	57,600	61,500	2026-0742	44,400
オ	residence-tax-exempt household	35,400	36,900	2026-0742	24,600

The table reflects ward and insurer pages current in July 2026 (as of 2026-07-31).¹² The income basis for National Health Insurance is prior-year income minus the 430,000 JPY basic deduction, summed across household members, with bands reset each August 1 (as of 2026-07-01).²⁴

Without a tax filing, the ward judges the band as ア, the highest bracket.² File the residence-tax return even in a zero-income year to hold the correct band.

Residents aged 70 and over

Residents aged 70 and over use a separate table with per-person outpatient caps plus household caps including admission.² Low-income bands sit lower, and the August 2026 revision added annual caps and revised outpatient caps alongside the monthly ones (as of 2026-07-01).²

Readers in this group should check the ward or insurer page for their exact outpatient and household pair. The main table above covers the under-70 working-age case only.

Two ways to pay: certificate up front or refund later

The default route is post-payment refund: pay the 30 percent at the counter, then claim back the excess above the ceiling.¹ The pre-payment route caps the counter bill itself: present the Limit Application Certificate or use the My Number insurance card so the facility charges only up to the ceiling.¹⁶

The diagram below shows the choice as a resident experiences it.⁶

The 限度額適用認定証 (gendogaku tekiyo ninteisho, "Limit Application Certificate") is the paper certificate for facilities without online eligibility verification or where the My Number is not registered.⁶ At verified facilities, the マイナ保険証 (maina hokensho, "My Number card registered for health-insurance use") shares the ceiling electronically with no separate form.⁶²

Low-income households use the combined 限度額適用・標準負担額減額認定証 (gendogaku tekiyo hyojun futangaku gengaku ninteisho, "combined ceiling and meal-charge reduction certificate") to unlock both the lower ceiling and reduced meal charges.⁶² A late certificate presentation can fail to apply to that bill, so arrange it before admission.⁵

Set up the My Number insurance link before planned admission

Registering the My Number card for insurance use removes the paper step at verified facilities. For a scheduled surgery or admission, confirm the link or request the certificate first rather than fronting the full 30 percent.⁶²

Where to apply by insurance type

Employees apply to their company health insurance society or Kyokai Kenpo branch, while National Health Insurance members apply at the municipal counter (as of 2026-07-01; confirm current figures with your insurer).¹⁶² In the ward example, the National Health Insurance benefit section handles online, mailed, and counter applications, with a phone check first for same-day issue.²

Post-payment claims run on a 2-year clock from the 1st of the month after treatment.⁴ In the ward example, the office mails a notice about 3 to 4 months after the treatment month, and transfer takes about 1.5 to 2 months after filing (as of 2026-07-01).⁴

Unpaid hospital bills cannot be paid out, and premium arrears can block certificate issuance as a rule.⁴² After one filing, the ward automates later payouts to the same account until the household head or account changes.⁴

What counts toward the cap

Only insured copayments count, never meals or private-room differentials.³ Counting runs per facility grouping: medical inpatient, medical outpatient, dental inpatient, and dental outpatient are tallied separately, with pharmacy dispensing added to the prescribing facility (as of 2026-07-01; confirm current figures with Kyokai Kenpo or your ward office).³⁴

Household members on the same insurance combine their copayments in the same month through 世帯合算 (setai gassan, "household aggregation").³ For residents under 70, only receipts of 21,000 JPY or more per facility grouping enter the combination (as of 2026-07-01).³⁴

Changing insurer, or changing from insured to dependent status, resets the 12-month multiple-occurrence count.³ Keep the same insurer record continuous where possible during long treatment.

Chronic treatment reduction

When ceiling-level months reach 3 or more within the prior 12 months including the treatment month, the 4th and later months use the lower 多数回該当 (tasūkai gaitō, "multiple-occurrence reduction") amount (as of 2026-07-31; confirm current figures with MHLW or your insurer).³⁴ For bracket ウ the reduced ceiling is 44,400 JPY both before and after the August 2026 revision (as of 2026-07-31).²³

The August 2026 revision held every multiple-occurrence amount flat while raising the monthly bases (as of 2026-07-31).¹ It also added a new 年間上限 (nenkan jogen, "annual cap") summed per household from August to next July, with the excess paid back (as of 2026-07-31).²

Current annual ceilings for under-70 households are 1.68M JPY for band ア, 1.11M JPY for イ, 530,000 JPY for ウ and エ, and 290,000 JPY for オ (as of 2026-07-31).²³ Annual-cap claims operate from the August 2026 treatment year, with the dedicated form cycle starting in August 2027 (as of 2026-07).³

A further subdivision of income bands is planned for August 2027, alongside multiple-occurrence relief for the lowest remuneration tier (as of 2026-07-31).¹ Treat that subdivision as announced policy, not current law, until the ministry publishes the in-force tables.

Separate long-term-disease relief covers dialysis-dependent renal failure, hemophilia, and specified antiviral treatment at 10,000 JPY per month, or 20,000 JPY for high-remuneration under-70 cases, through a specific-disease card.³ Ask the insurer about that card rather than the standard certificate when one of these diagnoses applies.

Good to know

A stay that straddles two calendar months counts twice

The ceiling resets on the 1st, so an admission spanning a month boundary draws one ceiling per month.² A single continuous stay can therefore cost two ceilings even though the treatment never paused.

Where the schedule is medically elective, starting early in the month concentrates covered cost under one ceiling. Confirm the plan with a licensed medical provider rather than shifting dates alone.

Private-room and meal charges have no cap

The differential bed charge, meal and living costs, and non-insured care carry no ceiling and stack on top of the capped amount.³⁴ Residents who budget only the monthly ceiling understate the real discharge bill.

Ask the hospital for the per-day bed differential and meal schedule at admission. Choosing a standard room where available keeps the uncapped portion smaller.

File the refund within two years

The refund window closes 2 years after the month following treatment, and unpaid hospital months cannot be paid out.⁴ Ward notices arrive months later, so track treatment months directly rather than waiting for the letter (as of 2026-07-01).⁴

Filing once usually automates later payouts to the same account.⁴ Report a household-head or account change promptly so automation does not misroute the transfer.

Confirm the current ceiling before planned treatment

Monthly bases rose in August 2026 while multiple-occurrence amounts stayed flat, and band subdivision is planned for August 2027 (as of 2026-07-31).¹⁶ A remembered 80,100 JPY base now understates the typical-income ceiling.

Check the MHLW page or your insurer at treatment time, and confirm which band the insurer assigned. Certificates issued from August 2026 carry a truncated validity to July 2027 because of the coming subdivision (as of 2026-07).⁶

See also

• Maina-Hokensho: Health Insurance Card Going Digital
• What Insurance Doesn't Cover
• Clinic vs. Hospital: The Two-Tier System
• NHI Enrollment at the Ward Office
• Shakai Hoken Overview

References

Footnotes

1. Ministry of Health, Labour and Welfare (MHLW). 「高額療養費制度を利用される皆さまへ」. Updated 2026-07-31. https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou_iryou/iryouhoken/juuyou/kougakuiryou/index.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴

2. Nerima Ward Office. 「入院等でこれから高額な医療費がかかる場合（限度額適用認定証の申請）」. Updated 2026-07-01. https://www.city.nerima.tokyo.jp/kurashi/nenkinhoken/kokuminkenkohoken/hoken_kyufu/madoguchi.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴

3. Japan Health Insurance Association (Kyokai Kenpo). 「高額療養費」. https://www.kyoukaikenpo.or.jp/benefit/high_cost_medical_expenses/002/index.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹

4. Nerima Ward Office. 「医療機関などで高額な医療費を支払ったとき（高額療養費の支給）」. Updated 2026-07-01. https://www.city.nerima.tokyo.jp/kurashi/nenkinhoken/kokuminkenkohoken/hoken_kyufu/kogaku_shikyu.html ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰

5. MHLW. "High-Cost Medical Expense Benefit (Eligibility Certificate for Ceiling-Amount Application)" English explainer PDF (en09.pdf), linked from the MHLW international health-care pages. https://www.mhlw.go.jp/seisakunitsuite/bunya/kenkou_iryou/iryou/kokusai/setsumeisiryo/dl/en09.pdf ↩ ↩²

6. Japan Health Insurance Association (Kyokai Kenpo). 「限度額適用認定証」. https://www.kyoukaikenpo.or.jp/benefit/high_cost_medical_expenses/001/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹